In making recommendations to the infrastructure and farm ministries concerning the maintenance of the nation's road overpasses, the internal affairs ministry has said that the number of overpasses at least 50 years old will rapidly increase and that serious damage frequently happens already.

We should remember the Aug. 1, 2007, collapse of an expressway bridge across America's Mississippi River, which killed 13 people and injured nearly 150 others. One of the slogans of the Hatoyama administration is to shift "from concrete to humans." But it must still do its best to ensure the safety of roads and bridges to protect human lives.

In Japan there are about 154,000 overpasses at least 15 meters long. If overpasses of at least two meters in length — across agricultural and forest roads — are included, the number increases to some 680,000. Local governments are responsible for maintaining 650,000 of them. Most overpasses were built in the 1960s and '70s. The percentage of overpasses 50 years old or older was around 6 percent in 2006, but is expected to increase to around 20 percent in 2016 and to nearly 50 percent in 2026.